- [Jitsi Video Bridge](https://jitsi.org/Projects/JitsiVideobridge) - WebRTC compatible Selective Forwarding Unit (SFU) that allows for multiuser video communication. ([Source Code](https://github.com/jitsi/jitsi-videobridge)) `Apache-2.0``Java`
- [Kandan](http://getkandan.com/) - Kandan is an Open Source Alternative to HipChat. ([Source Code](https://github.com/kandanapp/kandan)) `AGPL-3.0``Ruby`
- [KChat](https://github.com/php-kchat/kchat) - PHP Based Live Chat Aplication. `Apache-2.0``PHP`
- [Lets-Chat](http://sdelements.github.io/lets-chat/) - Self hosted chat suite written in Node. ([Source Code](https://github.com/sdelements/lets-chat)) `MIT``Nodejs`
- [Live Helper Chat](http://livehelperchat.com/) - Live Support chat for your website. ([Source Code](https://github.com/LiveHelperChat/livehelperchat)) `Apache-2.0``PHP`
- [Mattermost](http://www.mattermost.org/) - Open-source, on-prem Slack-alternative. It can be integrated with [Gitlab](https://about.gitlab.com/). ([Source Code](https://github.com/mattermost/platform)) `AGPL-3.0/Apache``Go`